Electromagnetic signaling apparatus.



C. H. NORTH.

ELECTROMAGNETIC SIGNALING APPARATUS.

APPLICATION FILED FEB. 9, 1907.

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CHARLES H. NORTH, OF CLEVELAND, OHIO, ASSIGNOR TO THE NORTH ELECTRIC COMPANY, OF GALION, OHIO, A CORPORATION OF OHIO.

Specification of Letters Patent.

Patented Apr. 6, 1915-.

Application filed February 9, 1907; Serial No. 356,567.

To all whom it may concern:

Be it known that I, CHARLES H. NORTH, a citizen of the United States of America, and a resident of Cleveland, in the county of Ouyahoga and State of Ohio, have invented certain new and useful Improvements in Electromagnetic Signaling Apparatus, of which the following is a specification.

My invention relates to improvements in electromagnetic signaling apparatus, and is herein embodied in a polarized bell adapted for use upon poly-station telephone lines.

The object of my invention has been to simplify and improve the construction of signaling apparatus, and particularly that relating to the so-called harmonic type, although my improvements are' applicable to other uses, and in other types of bell than the ones employed in harmonic signaling, since, broadly speaking, improvements in bells of harmonic type meet certain requirements of an ordinary magneto ringer.

The features wherein I have improved upon signaling apparatus of the prior art are both magnetic and mechanical in character, and will be explained in connection with the preferred type of bell shown in the drawings.

It is highly desirable in electric bells, that the bell-tapper shall vibrate upon a fixed point as a pivot, while with harmonic bells it is practically necessary that the belltapper shall take the form of a reed, suitably tuned to respond to currents of definite characteristics. Numerous types of tunedreed bells have been devised, but those which have been practically used to any extent, follow the general lines of a magneto bell, in

having an armature positioned to oscillate before the presented ends of the electromagnet, while the pivot is displaced by some form of spring-mounting. These constructions involve the mounting of the bell-tap per, the tapper-rod, the armature and spring in such manner that the several parts are sought to be united, with greater or less suecess, as a unitary whole, but this subdivision of parts not only is a step toward reater complexity, but detracts from perect harmonic actuation.

In my improved bell, I have departed from the general accepted lines of construction, and have formed the vibratin reed and armature from a single piece of steel, ri gi (1] y secured below to the magnet frame, and

vibrating between the adjustable pole-pieces, and intermediate of the electro-magnet. In order to obtain a strong polarizing effect, the permanent magnet is placed directly in line with this armature, which partially closes the magnetic circuit thereof, while an eccentric mounting and adjustment of novel form is provided for securing the close and rigid adjustment, both of the gongs and the pole-pieces. The pole-pieces, in the harmonic type of bell, are positioned but a short distance from, and at either side of the tuned-reed and armature, and alternately act as stops for permitting the momentary flexure of the upper portion of the reed and bell-tapper. All of the foregoing features, as well as others, will be more readily appreciated by making reference to the accompanying drawings, wherein Figure I is a view in front elevation of an electromagnetic signaling bell embodying my invention. Fig. II is a side elevation thereof; one of the bell gongs and itssupporting stem being removed. Fig. III is a plan view partially in section on line III-III, Fig. I. Figs. IV and V are de-;

tails illustrating the eccentric adjustment and mounting of a supporting post. Fig. VI shows in plan the adjusting wrench.

Fig. VII is a detail of a higher-frequency tuned-reed and tapper, and Fig. VIII is a detail, partially in section, showing a stamped metal supporting plate, shaped preferably from zinc or brass, and illustrating, as well, the eccentric adjustment for the pole-pieces.

Throughout the several figures of the drawings, the same character of reference is employed to designate similar parts.

The supporting plate a is made from nonmagnetic metal, such as a bronze casting, or

a zinc stamping respectively shown in Figs. III and VIII. This part has considerable thickness or body to provide for the rigid mounting and relative permanence ofadustment of the various parts. The cores of the electro-magnet are mechanically united at their upper ends by means of the tapped bolts a, extending therein through the supporting plate a, and magnetically and mechanicallfy united at their lower ends b means 0 the magnetic bridge-piece b.

U-shaped permanent magnet c is attached centrally to the bridge-piece, and extends immediately above the central opening in formed, at the points d and (l in order that it may be more readily flexed at these points.

Near the upper portion of the reed-armature are positioned the adjustable polepieces 6 which have a longitudinal movement in the ways or slides a, under the influence of their respective eccentrics e. Thus these pole-pieces may be adjusted toward or from the reed-armature, and in the harmonic type of bell, are so positioned that they act as stops against which the reedarmature abuts to cause a fiexure of the upper portion for the purpose of striking a blow upon the corresponding gong g. The proper adjustment of each of these polepieces, having been determined by experlment, the parts are secured in their relative position by tightening the tapped bolts a,

and thereby locking the respective cores, ec-

centrics and pole-pieces firmly against the non-magnetic plate a. Substantially similar adjustments are provided for the gongs g, which are carried upon posts f seated respectively within slots a in p ate a. The lower end of each of said posts, has a shoulder f formed thereon engaging an eccentric e, beneath which is a flattened portion f closelv engaging the side walls of the slot, and a nut f turns upon the tapped end f for securing the gong and post rigidly in their positions of adjustment toward and from the bell-tapper. Ribs or ways a? are provided, within which the eccentric e may 0 rotated to efi'ect the accurate adjustment of the gongs. Screws h h enter tapped openings in the plate a, and serve to secure the entire structure to the bell box, or other supporting part. 1

Having now explained the e'neral structural features of my improve bell, I may now point out some of the advanta es thereof, and its mode of installation an use.

- Assuming that several of the bells are to be employed upon a party line, such bells will be difi'erently tuned by having belltappers d'-' of different weights, fixedly positioned the proper distance upon the upper end of the respective reed-armature to respend to signaling currents of corresponding periodicity. Each of these signaling apphances when positioned at the appropriate sub-station, will be adjusted, by first loosening the bolts a with wrench i, and inserting the pin z'" within openings in the respective eccentrics e, thereby turning said eccentrics until the pole-pieces are properly spaced to act as stops for the vibrating reed-armature, when influenced by the corresponding current. The bell gongs are then similarly adjusted to be struck alternately by the throw of the bell-tapper at when the reed-armature is checked by the corresponding polepieces of the electro-magnet. Upon tightening the nuts F, the posts will be rigidly locked in position with respect to each other, the bell-tapper and the supporting plate a, and the device will require no further attention under normal conditions.

In order better to appreciate the improved eccentric adjustment of my invention, 1 may call attention to Fig. 111, wherein the eccentric 6 upon the left, is rotated to position the bell post f about midway within its slot, while the eccentric 6 upon the right, has been turned to obtain a much closer adjustment of the gong toward the bell-tapper. Inasmuch as these posts are movable only within the slots, the gongs must be presented toward the bell-tapper in line therewith, instead of being adjustable toward and from the same in an arc-shaped path.

The importance of having the several parts as rigid and relatively permanent in adjustment as possible, cannot well be over-estimated, and the same is true of the simplicity of design with respect to the vibrating members. In my improved hell, it is seen that the reed-armature directly carries the belltapper, which will be of varying weight, but properly positioned to strike each of the gongs a direct blow; the same being rigidly held in line therewith, while the pole-pieces are so firmly fixed in position against the underside of the supporting plate, as t'dform absolutely rigid stops to efi'ect the sudden fiexure and rebound of the bell-tapper. Positioned as it is, the permanent magnet readily closes the lines of magnetic vforce, or

a large portion thereof, directly through the reed-armature, thereby strongly magnetizing the same and rendering the bell much more efiicient and prompt in responding to the proper selective current, than in structures of the prior art. Moreover, the power. is mm parted to the unitary reed-armature in a position immediately adjacent to its point of fiexure or throw d thus avoiding any tendency to the formation of nodes within the reed. This high efficiency, moreover, is largely contributed to by the integral reedarmature, which preferably is positioned at the neutral point of the electro-magnet, and extending parallel or in line with the cores thereof, 'serves to close the electro-magnetic circuit through the closely adjacent pole pieces. It is seen that the parts all lie substantially in the plane of the armatures vibration, so that the adjustment of the pole pieces and gongs cannot impair the efliciency of the device in any degree. Thus the arr'natime itself lies in direct line for closing'the magnetic circuits both of the ermanent magnet and the lectro-magnet, an the structure is accordingly rendered more sensitive to the proper se ective current, than in any device with which I am acquainted.

The preferred alternating current of proper periodicity, is one which shall cause the armature to 01m to each pole-piece for the briefest space 0 time, dependent upon the frequency of alternation, whereby the reed-armature is held directly against the respective pole-pieces, while the flexure and reactance of the upper portion of said reedarmature takes place, as described. This maintains the reed in perfect tune with its actuating current, and makes certain that a quick blow will be struck upon the gong at each vibration of the armature.

In the eccentric mounting and adjustment herein provided for the pole-pieces and the gongs, .is found a thoroughly reliable means, and one of extreme simpllcity, cheapness and rigidity for securing the relative positioning of the parts thus equipped. This is much to be preferred to a screw-adjustment, while sufliciently close and accurate for any practical purpose and affording considerably more rigidity and strength.

A minor feature of advantage in the structure shown, is the provision of the special wrench shown in Fig. VI, with which the entire structure may be assembled, and adjusted, rather than to require the use of a screw-driver and wrenches of varying sizes for these purposes.

Althou H I have explained with considerable detail the several features of the preferred type of bell for harmonic signaling, as intimated above, my improvements are adapted for use as a si aling bell upon individual lines, thereby insuring many of the advantages before adverted to. Not only this, but features of my improvements may be found applicable in other electro-magnetic devices, than the ones herein referred to.

Having now described the preferred structure embodying my invention, I claim as new and desire to secure by Letters Patent, together with such modifications as may be made by mere skill, the following 1. In an electro-magnetic signaling device, the combination with an electro-magnet, of an armature positioned between and substantially parallel with the cores thereof, a polarizing magnet closing its circuit partially through said armature, and adjustable polepieces upon the electro-magnet between which said armature is adapted to vibrate, substantially as set forth.

2. In an electro-magnetic signaling device, the combination with an electro-ma et of a magnetic reed rigidly secured at its lower end between the cores thereof and in sub stantially the same plane, a larizing' magnet closing its circmt partia y through said reed, and pole-pieces u on the electro-amagn et between which sai reed is adapted to vibrate, substantially as set forth.

3. In an electro-magnetic signaling device, the combination with a vibrating armature, of a polarizing magnet positioned substantially parallel therewith havin extended inclosmg poles, and partially c osing its circult throughsaid armature, and an electromagnet influencing the armature to vibrate when traversed by alternating currents, substantially as set forth.

:1. In an electro-magnetic signaling appllance, the combination with an electro magnet, of an armature mounted to vibrate between the poles thereof and a U-shaped polarizing magnet positioned partially to inclosethe armature and having its poles substantially bridged thereby, and means carried by the armature for efiecting a signal, substantially as set forth.

5. In a device of the class described, the

ture, substantially as set forth.

6. In a device of the class described, the

. combination with an electro-magnet, of adjustable pole-pieces extending therefrom, guides therefor, an eccentric-part associated with each of said pole-pieces to obtain their respective adjustment, a non-magnetic support for said parts, and an armature positioned to be vibrated by the pole-pieces, substantially as set forth.

7. In a device of the class described, the combination with a non-magnetic supporting plate, of guides provided thereon, soft iron pole-pieces adjustable within the guides, an electro-magnet with its cores presented to said pole-pieces, eccentrics engaging the cores and pole-pieces, whereby the latter may be adjusted, and an armature vibrating between said pole-pieces, substantially as set forth. v

8. In an electric signaling bell, the combination with a non-magnetic supporting plate, an electro-magnet secured thereto, an armature positioned between and substantially'parallel with the cores of the electromagnet with a part extending through the supporting plate, a bell tapper thereon, and

gongs positioned to be sounded by the vi- I plate, an electro-magnet secured thereto, an

armature positioned between and substantially parallel with the cores of the electromagnet with a part extending through the supporting plate, a bell tapper thereon, a polarizing magnet posit oned to excite the armature, and gongs positloned to be sounded by the vibration of the bell-tapper substantially as set forth.

10. In an electric bell, the combination with a supporting member, of ways or guides provided thereon substantlally at right angles with each other, an adjustable, I

member, a gong mounted thereon, an eccentric positioned between the supporting and adjusted in position with respect to each other, and means for securing them in their positions of adjustment, substantially as set forth. I

12. In a harmonic signaling bell, the combination with an electro-magnet of a reedarmatiire fixedly secured at one end between the cores thereof and in substantially. the same plane, pole-pieces between which said armature vibrates, a polarizing magnet, a

' bell-tapper carried by vsaid armature, and

gongs adapted to be sounded by the belltapper, substantially as set forth.

13. In a harmonic signaling bell, the combination with an electro-magnet of areedarmature fixedly secured at one end between the cores thereof, pole-pieces, between which said armature vibrates, a polarizing magnet, a bell-tapper carriedby said armature, gongs adapted to be sounded by the bell-tapper, and means comprising eccentric members and stationary guides, for securing the relative adjustment of the pole-pieces and gongs with respect to the armature, substantially as set forth.

14. In a harmonic signaling bell, the combination with a nonmagnetic supporting plate, an electro-magnet secured thereto, with its cores presented toward said plate,

adjustable pole-pieces thereon, a reed-armature fixedly attached at one end between said cores and pole-pieces and substantially parallel with the cores, a polarizing electromagnet, a bell-tapper carried by the armature, and gongs positioned to be sounded by the bell-tapper, substantially as set forth.

15. In a device of the class described, the

adjustable members, for securing the relative messes combination with an electro-magnet, of a reed armature mounted to be vibrated thereby, and a polarizing magnet positioned substantially parallel to said armature with its polar extremities extending closely adjacent to the armature body at widely separated points, whereby the magnetic circuit of said polarizing magnet is substantially closed through the armature to render it sensitive to selective or alternating currents, substantially as set forth.

16; In a device of the class described, the combination with an electro-magnet, of an armature positioned between the cores thereof and adaptedtobe vibrated by the electromagnet, and a polarizing magnet positioned substantially parallel to said armature with its polar extremities extending closely adjacent to the armature body, whereby the magnetic circuit of said polarizing magnet is substantially closed through the armature to render it sensitive to alternating currents, substantially as set forth.

17. In an electric signaling bell, the combination with an electroemagnet, of an integral reed-armature rigidly secured substantially at the neutral point of said electromagnet and parallel with its cores in position to be vibrated thereby, adjustable polepieces between which said armature vibrates, bell gongs,-and a bell-tapper carried by the armature for sounding said gongs, substantially as set forth.

18. In an electric bell, the combination with an electro-magnet of an integral reedarmature secured substantially at theneutral point of said electro-magnet and parallel with the cores thereof, pole-pieces between which said armature vibrates alter- -nately to complete the magnetic circuit, a

' signaling member, substantially as set forth.

20. In an electric bell, the combination with a polarizing magnet, an associated electro-magnet, an"integral reed-armature parallel therewith and secured substantially at the neutral point of the electro-magnet and intermediately of reduced cross-section to assist flexure, adjustable pole-pieces between which the armature is designed to vibrate, a bell gong, and an associated belltapper carried by the armature, substantially as set forth.

21. In an electro-magnetic signaling apparatus, the combination with a double cored, electro-magnet, of an armature positioned between and parallel with said cores to be vibrated thereby and alternately close magnetic circuits therewith, a polarizing magnet, a signaling member, and means carried by the vibrating armature for actuating said signaling member, substantially as set forth.

22. In the electro-magnetic signaling appliance, the combination with a supporting plate, of ways or guides formed thereon respectively for the gongs and the pole pieces, an electro-magnet, adjustable pole pieces therefor, an armature actuated by said pole-pieces in the vertical plane of adjustment of their axes, whereby the efiiciency of the device is maintained under different conditions of adjustment, bell-gongs, a polarizing magnet, and means associated with the armature for efl ecting the signal, substantially as set forth.

23. In an electro-magnetic signaling device, the combination with the actuating eleetro-magnet thereof, of a vibrating armature mounted substantially at the neutral point of said electro-magnet between its cores and extending in a plane parallel therewith, a permanent magnet positioned with its poles respectively adjacent to the ends of said armature, and means actuated by said armature for effecting the signal, substantially as set forth.

24. In an electro-magnetic signaling device, the combination with the actuating electro-magnet thereof, of a vibrating armature mounted substantially at the neutral point of said electro-magnet between its cores and extending in a plane parallel therewith; said armature being substantially the length of said magnet cores, pole pieces upon the extremities of said cores between which the armature is actuated, a permanent magnet with its poles substantially adjacent to and inclosing the ends of the armature, and means associated with said armature for effecting the signal, substantially as set forth.

25. In an electro-magnetic signaling device, the combination with the actuating electro-magnet thereof, of a vibrating armature mounted substantially at the neutral point of said electro-magnet between its cores and extending in a plane parallel therewith; said armature being rigidly mounted at one end and presenting an integral flexible body portion, pole pieces upon the magnet cores adjacent to the free end of the armature between which it is adapted to vibrate, a polarizing magnet, a gong, and a weight carried by the armature in position to strike said gong, substantially as set forth.

26. In an electro-magnetic signaling device, the combination with a central reedarmature, of a permanent magnet positioned with its poles adjacent to the ends of said armature, an electro-magnet, pole pieces thereon serving as stops between which the free end of the armature vibrates, adjacent gongs, and a weight carried by the armature for sounding the same, substantially as set forth., Y

27. In a harmonic bell-structure, the combination with an electro-magnet, of a central reed-armature mounted at substantially the neutral point of said electro-magnet, pole-pieces serving as stops adjacent to the free end of the armature, a polarizing magnet positioned with its poles respectively adjacent to the ends of the armature, adjacent gongs; the several parts all being mounted substantially in the plane of the armatures vibration, and a weight adapted to sound said gongs when actuated by the armature, substantially as set forth.

28. In a harmonic bell-structure, the combination with 'an electro-magnet, of a central reed-armature mounted at substantially the neutral point of said electro-magnet, pole-pieces serving as stops adjacent to the free end of the armature, a polarizing magnet positioned with its poles respectively adjacent to the ends of the armature, ad acent gongs; the several parts all being mounted substantially in the plane of the armatures vibration, means for adjusting the pole pieces and gongs substantially in the plane of said armatures vibration, and a weight for sounding the gongs when actuated by the armature, substantially as set forth.

Signed at Cleveland, this 7th day of February, 1907, in the presence of the undersigned witnesses.

CHARLES H. NORTH. Witnesses J. G. MITCHELL, ALBERT LYNN LAWRENCE. 

